Blocker synchronizer



Nov. 19, 1940'n s. o. wmTE UAL 2,221,899

BLOCKER SYNCHRONIZER Filed Jun 1l, 1938 2 Sheets-Sheet 1 35 Z7 J9 W ylllllll-IIII' l Nv.19,194o. s, C,- WHWE ETAL 2,221,899

' BLOCKER SYNCHRONIZER A Filed Jupe 11, 1958v 2 sheets-sheet 2 PatentedNov. 19, 1940 PATENT oFFIcE BLOCKER SYNCHRONIZER Samuel '0. White andI-almer Orl',- Muncie, Ind.,

assignors to Borg-Warner Corporation, Chicago, Ill., a corporation ofIllinois Application June 11, 1938, Serial No. 213,132

` 23 Claims. (Cl, 192-53) This invention relates to synchronizing changespeed gear transmissions of the type employed, for example, in motorvehicles wherein there is provided means for effecting synchronizationof a pair or pairs of torque-transmitting members preparatory toconnecting said members in positive drive engagement with each other.

'Ihe invention is particularly directed to synchronizing transmissionsof the type 'wherein vthe synchronizing means comprises friction clutchelements drivingly associated with the respective torque-transmittingmembers and adapted to be moved into engagement with each other in theinitial stage of the shifting movement,. and

l5 wherein there is incorporated so-called blocker" vmechanism forpreventing the positive drive ensagement of the members prior to thetime that synchronization is effected.

An object of the invention is to provide a trans- 2 mission synchronizerof this type, having a minimumnumber of parts, and which is extremelyinexpensive and simple to manufacture.

Another object is to provide such a transmission synchronizer whichrequires a minimum of g5 manual eiort to effect blocking of the movable3g chronization has been attained.

In the past it has been universally considered necessary bymanufacturers of automobiles and by manufacturers of transmissiongearing, to'

employ between the movable clutch element and 35 vthe thrust element ofa synchronizing mechanism, a detent or poppet connection having abreak-away action for the purpose of transmitting movement from saidmovable clutch element to said thrust element for developing axial pres-0 sure against the blocker synchronizer rings of the mechanism. In suchmechanisms, after having eiiected synchronization by initial movement ofthe shifter member' in' the direction of the gear position that has beenselected, it is necessary 45 to increase the force exerted against theshifter member in order to effect the break-away release l oftliemovable clutch member fromthe thrust element and allow the .movableclutch element to advance through the blocker teeth of the 5o blockersynchronizer ring into clutching engagement with the clutch teeth of thegear that. has been selected.

One of the objects of the present invention is to provide atransmissionof the type described 55 above, in which the resistanceto shifting ofthe lmovable clutch element is uniform and relatively low until themovable clutch element encounters the blocker mechanism, so that theonly point of appreciable resistance to shifting will be that point atwhich the shifting operationmust be 5 halted until synchronization iscomplete, thus eliminating any confusion between the resistance offeredby the detent or poppet mechanism and that which is set up by theblocker mechanism, and automatically reducing the resistance to a 10very low quantity when synchronization has been completed, thus to moredefinitely, inform the operator that synchronization has been effected.

The foregoing objectsare accomplished, in general, by the provision of asynchronizing transmission of the type referred to above, in whichmovement is transferred from the movable clutch element to theblocker-synchronizer ring by means of thrust members arranged to receivemovement from the movable clutch element solely through the medium of apurely frctlonal en gagement between coacting faces that are parallel tothe direction of shifting movement. In particular, the inventionprovides lan arrangement wherein the thrust-transmitting engagementbetween the thrust-transmitting means and the movable clutch element isvaried roughly in accordance with the amount of relative rotationexisting between the members to be synchronized, the thrust-transmittingmeans being urged under pressure into its frictional engagement with themovable clutch element while relative rotation exists, and such pressurebeing automatically relaxed when synchronization is attained, so as tosubstantially remove the frictional resistance to advance of the movableclutch element. Y i

Other objects, the advantages and uses of the invention will becomeapparent after reading the following specication and claims. and afterconsideration ofthe drawings forming a part or the specification,wherein:

Fig. lis an axial sectional view through a transmission synchronizerembodying the invention; i

Fig. 2 is a transverse sectional view thereof taken on the line 2-2' ofFig. 1; f

Fig. 3 is a detail sectional view thereof taken on the line 3-.3 of Fig.2; 50,

Fig. 4 is an axial sectional view, illustrating the operation of theinvention;

Fig. l5 is aA transverse sectional view through the hub and movable jawclutch element of a modified form of the invention; 55

Fig. 6 is an axial sectional view of another modification oftheinvention: v

Fig. 7 is a transverse sectional view taken as indicated by the line'I-I of Fig. 6;

Fig. 8 is an axial sectional view of a further modified form of theinvention; and

Fig. 9 is a transverse sectional modified form of the invention.

As illustrative of the general nature of the invention, reference maybemade rst to Figs. 1 and 2 of the drawings. The invention is thereinshown as applied to the type of synchronizing transmission disclosed inthe application of Sam uel O. White, Serial No. 168,317, filed October11, 193'?. Such a transmission may include a torque-transmitting memberIll, forming the rear end of the drive shaft of the transmission, andtorque-transmitting members, including the driven shaft I I, piloted, asat i2, in the member I0, and the hub member I3 splined, as at I4, on thedriven `shait II and secured against axial movement by retaining ringsI5 and IB. A positive drive connection is adapted to be establishedbetween the torque-transmitting members IS and Il, I3," or betweenthereduction geared torquetransmitting member II and thetorque-transmitting members II, I3, by an axially movable view ofanother f' jaw clutch element I8, adapted to be shifted axially by ashifting fork I3 into positive clutching engagement with clutch teeth26, formed on the torque-transmitting member I0, or clutch teeth 2Iformed on the torque-transmitting member I l. 'Io this end, the movableclutch element I8 is formed with internal clutch teeth 22, in splinedengagement with teeth 23 forming the periphery of the hub member I3, andadapted to engagethe clutch teeth or 2| when moved axially.

The torque-transmitting member I'I comprises part o1 a reduction geartrain driven from a pinion 24 on the drive shaft I B, through the mediumof `a conventional countershaft, such as is shown in the Whiteapplication above referred to. Upon being moved into clutchingengagement with the clutch teeth 20, the clutch member I8 willreceiverotation from' the drive shaft I0 and transmit 'it directlythrough the hub I3 to the drivenishaft 'll. Upon'being moved in theopposite "directionj intoj 'clutching engagement with the teeth 2l', theclutch member I8 will receive "rotation fi'm the torque-transmittingmemb'e'r'f'I'I through the countershaft just referred to, and, willtransmitit through the hub member I3 to the driven shaft II.`

In order to synchronize a torquetransmitting member I0 or I'I with thehub I3, preparatory to establishing such clutching engagement, weprovide a pair of synchroniser rings 25 each including asubstantiallycylindrical collar portion 26 rotatably Aheating in anannular groove 21 extending axially into the hub member I3, and aradially outwardly extending ange 28 formed with blocker teeth 23between which the teeth 22 of the movable clutch lelement must passbefore the clutchingengagement may be had with .the clutch teeth 23 or2l." The opposed ends of the teeth 22 and 29 may be chamfered, as shownat 30 and 3| respectively in Fig. 31. The synchronizer rings 2 5 areprovided with internal conical clutch faces 32 adapted to engageexternalcon# ical clutch faces of coacting clutch elements 33 and 34respectively, formed on the torque-transmitting members I0 and I'I. Therings 2S are adapted to be located and supported --by thef clutch faces'33 and. "Interve'ziing oil' bers 35 will develop an initial stage mentbetween the friction clutch faces 33 or 3l,

and their cooperating friction faces 32 upon the rings 25, the rings 25are moved axially by axial thrust transmitted to them fromthe movableclutch element through the mediumof thrust members 35. 'The thrustmembers 35 are preferably cylindrical in form, and may be simply andinexpensively made by cutting sections from a cylindrical rod of coldrolled steel. They are mounted in substantially semi-cylindrical notches31 formed in the interior of the shiftable clutch '.element I8,preferably in centered relation between two of the teeth 22. 'I'heintermediate regions of the thrust members are received in correspondingnotches 36 in the hub I3. Their ends are received in elongated recesses38 in the synchronizer rings 25. Between the center of 'each recess 38and its curved end regions 40 are inclined 'ramps 4I which are adapted,when the synchronizer ring moves to either side of its'centered positionwith respect to the movable clutch element, to engage the thrust members433am! wedge them more tightly into their notches 31. The notches 3l areconformed closely to the surfaces of the thrust members so as to give-a. relatively large area of engagement between the two.

Engagement of theends of the thrust 'rods 3B in the recesses 38 provideslost motion connections between the synchronizer rings and the hub andmovable clutch element, wherebya synchronizer ring may shift from aposition in which the blocker teeth 29 arev eective to block axialshifting movement of the movable-clutch element I8, to a position inwhich it allows the movable clutch element to pass on into clutching Yever, it is to be understood that thepresent in` vention is not intendedto be limited to this type of lost motion connection.

In the initial stage of the .shifting operation, frictional engagementof the thrust members 35 with the interior of the movable clutch elementI8 causes the thrust members to be moved axially with the movable clutchelement, so that pressure will be exerted by the ends of the thrustmembers 35 against a synchronizer blocker ring 25.

The thrust thus transmitted by the thrust memof frictional clutchingengagement between' the synchronizer ring and one of the drivingmembers, which may, preferably,4 be only suilicient 4to bias thesynchronizer ring to one limit of its lost motion connectiom This willestablish the blocking relation of the teeth 29 with respect to theteeth 22, whereby continued pressure against the shift fork I9 .willcause the movable clutch element to advance into engagement with theblocker synchronizer ring 4and to exert axial pressure threagainstsuchas to establish the second's'tage offrictinal clutching engagement,effective for causing 4thefjsvnchronizer ring and the driving--memberY--with which it is thus nationally encased. tc approach the samespeedofrotation.

When synchronization is reached, there jwill be a momentary reversalofthe relative directions of rotation of the torque-transmitting memberswith relation to each other, causing the synchronizer ring to beoscillated toward its other limit of lost vmotion movement relative tothe hub I 3, and in so doing, it will reach a position wherein theinternal teeth 22 of the shiftable clutch element I8 are in registerwith the spaces between the blocker teeth 29, whereupon the teeth 22which have already commenced to move into such spaces owing tothechamfered faces 30 and 3i of the respective sets of teeth, will, underthe continuous urging pressure of the shifting member I9, slide betweenthe teeth 29 and into engagement with the now synchronized clutch teeth2Il or"2l. In this stage of movement, the resistance to advance of themovable clutch element' has been reduced to the relatively smallresistance occasioned by frictional engagement between the thrustmembers and the movable clutch element. There is no occasion forovercoming the resistance of a spring detent connec-` tion between thesetwo members. As a result, the completion of theshift is very smooth andeasy.

'I'he clearances between the friction clutch faces, .when the movableclutch element is in neutral position, are preferably soarranged that alm of oil may exist between these faces and develop, under relativerotation thereof, a slight oil drag, tending constantly to bias thesynchronizer rings toward blocking positions.

Oil drag between the friction clutch faces tends to bias thesynchronizer rings suillciently to maintain the ramps 4I in engagementwith the thrust members 35,' whereby to assure contact between thelatter and the notches 31, irrespective of speed of rotation, so .thatthe thrust members will commence to exert thrust against `a synchronizerring when shifting movement commences.

The thrust elements 35 transmit thrust to the rings 25 by engagingagainst shoulders 42 by the recesses 38 beintr terminated short of theouter iat-es of thrings 25.

. The engagement of the thrust members 35 by the ramps 4I causes thethrust bars to be fd /Jwedged into increased frictional engagement withthe notches 31, thereby increasing the amount of thrust that can betransmitted blocker teeth into 'clutching engagement with the clutchteeth 2li or 2|. l

It is contemplated that the clearancel between the thrust bars 35 andthe notches 36, 31 and 38 respectively, may be such that during thewedginto the central depressed region of its recess 38.i

The fritional contact of the edge of the movable clutch element, at 5I,will thus be even more eflectiveto move the thrust bar in the directionindicated by the arrow 52, than if the surface of the bar remainedexactly parallel to the direction 'of movement. The bar may contact thehub, as at 53, without -thereby developing any appreciable resistance toaxial advance, since such -contact would be only a brushing one ascontrasted to the wedging contact -at 5I. the parts could -be arrangedso that there would be-no contact at all between the hub andthe thrustbars, as the bars could the synchronizer rings. i

It would be possible to form the recesses 38 so as to be ln substantialcontact with the thrust members 35 at all times, asin the form shown in.

- Fig. 5. In this form of the invention, we form the central regions ofthe recesses 38e with bot-l tom surfaces curved coaxially with themaioraxis of the synchronizer, in order to allow the re- "quired lostmotion shifting of the synchronizer ing action described with referenceto Figs. 1 to 3.

For-some installations, it may be desirable to provide means for lightlyspring-'urging the thrust bars into engagement with the movable clutchelement. Such means may comprise, asi-40 shown in Figa-6 and 7, anannular or semi-annuahead of the hun as, between-melma@ mehr@reriiigtii'pmvided with indented Actually,`

be supported by lar spring 45 of light spring wire, mounted just/fRportions 46 in engagement with one end of the@ sion of thrust,irrespective cf the speed of rota-15@ tion 9i fthe parts.

throughv the thrust members 35, such increasefl"/Ather advantage of thisform of the mven" -f/"hriction clutch faces which in turn increases 'Yco *""operation proceeds, so as to .produce a smooth acceleration` ofclutching action, and thereby effeet synchronization in a minimum periodof time, andA yet with maximum smoothness. As

' the torque-transmitting members approach synchronization, however, theWedging pressure against the thrust members 35 will be relaxed, and atthe moment of synchronization, will be fully released, owing 4to theshifting of the synf chronizer ring back to the central position f' itslost motion connection. This relaxato of wedgtion arises from the factthat when lthe movable clutch element I8 is shifted into positiveclutching engagement with the teeth 2| of the terq 155 transmittingmember I1, the springs 45 willtilt the bars 35 slightly, so that theirends opposite the springs will engage in the recesses 38, while theirintermediate regions engage the corners V formed between the notches 31and the the movable clutch element. I8. Whenth/e movable clutch elementis retunieto/neutral position, its engagement with/the bars 35 may tendgage f the modified form of the invention shown in Fig. 8, the thrustbars 35g are each formed in telescoping sections including a shellmember 41 to drag the synchron@ ring in engagement with the frieht1element 34, out of clutch en-V ing action will relax thitafdjn/gesismeto having a bore 48, and a plunger 49 mounted in 70 further axialmove/ment of the shiftable clutch the bore 48 and urged outwardly by alight c0m` element relative/to the thrust members which was produced bysuch wedging action, and under very light pressure of the shifting forkI9, the

pression spring 5I), received in the bore 48. Thus the thrust bars 35gserve vto exert a very light axial pressure against the synchronizerrings 25,

movable clutch element will advance through the suihcient to produce aconstant light engagement sections from a rod of cold rolled steel.

between the friction clutch faces resulting in a drag which serves tobias the synchronizer rings constantly in blocking relationship, for thepurposes set forth with respect to the form shown in Fig. l. I

The thrust bars need not necessarily be cylindrical. For example, in theform of the invention shown in Fig. 9, the bars 35a are relatively wideand fiat, with bevelled corners 54 engaging. bevelled end faces 55 ofthe synchronizer ring notches 38a; The square edge Afaces 56 are adaptedto engage the side faces of separated teeth 22 of the movable clutchelement I8, and the outer faces 5l are adapted to engage the cornersofvintervening teeth, as at 58. The bars may be radially supported andcircumferentially positioned, either by resting in suitable depressionsin the hub (not shown), or by the provision of bottoms in the notches38a, as in the form shown in Figs. 1 and 2.

Biasing of the synchronizer ring will cause inclined faces 55 of notches38a to engage bevelled corners 54 of the bars 35a, so as to exert acamming action against the bars, tending to rotate them around theirlongitudinal axes, into binding engagement with the teeth 22' of themovable clutch element.

A device constructed in accordance with the present invention is ofmaximum simplicity and cheapness of construction. Savings are effectedby eliminating the necessity of lugs on the synchronizer rings forproviding lost motion connections, by eliminating springs, byeliminating poppet constructions, and by providing thrust members whichcan be produced simply by sawing The semi-circular notches, for examplethe notchY 31 in the shiftable clutch element of Figs. 1 to 3 inclusive,may be broached with the same tool.

that breaches the internal teeth 22.4 'I'he rings 25, which preferablyare of bronze, may becast,

and the recesses 38 formed in the casting operav tion.

We claim:

1. In a synchronizing transmission, a pair of axially alignedtorque-transmitting members, movable jaw clutch and synchronizerelements drivingly associated with one member, said clutch element beingmovable axially and said synchronizer element being adapted to be urgedunder axial pressure into positive. clutching and frictionaldrivingengagement, respectively, with jaw and friction clutch elementsdrivingly associated with the other member, and a thrustelement arrangedto transmit axial thrust to said synchro- -nizer element and tofrictionally engage anv interiorsurface of said movable clutch elementwith a radially outwardly directed pressure developed as a result ofrelative rotation between said synchronizer elent and the member withwhich it is engaged so as to receive' axial thrust from said movableclutch element.

2. In a synchronizing transmission, cpm of axially alignedtorque-transmitting members, movable jaw clutch and synchronizerelements drivingly associated with one member, said clutch element beingmovable axially and said nizer element being adapted to be urged underaxial pressure into positive clutching and frictional drivingengagement, respectively, with Jaw' and friction clutch elementsdrivingly associated with the other member, and a thrust elementarranged to transmit axial thrust tosaid synchronizer element and tofrictionally engage an interior surface of said movableelutch elementlchronizer: element an its cooperating with a radially outwardlydirected pressure developed as a. result ofl relative rotation betweensaid synchronizer element and the member with which it is engaged so asto receive axial thrust from said movable clutch element, and to relax 5such engagement when synchronization is attained. l 3. In asynchronizing transmission, a pair of axially alignedtorque-transmitting members, movable jaw clutch and synchronizerelements 10 drivingly associated with one member. said clutch elementbeing movable' axially and said synchronizer element being adapted to beurged under axial pressure into positive clutching and 'frictionaldriving engagement, respectively, with jaw and friction clutch elementsdrivingly associated with the other member, and a thrust elementarranged to transmit axial thrust to said synchronizer element and tofrictionally engage an in` terior surface of said movablev clutchelement with a radially outwardly directed pressure varying in intensityin response to variations in the rate of 'relative rotation between saidsynchronizer element and the member with which it is engaged, whereby toreceive axial thrust from said movable clutch element.

4. In a synchronizing transmission, alpairof/ ./eaxially valignedtorque-1aismittingl members, movable jaw clutch and synchronizerelements drivingly associated with one member, said clutch element beingmovable axially and said synchro- .nizer element being adapted to beurged under axial pressure into positive `clutching and frictionaldriving engagement, respectively, with jaw and friction clutch elementsdrivingly associated with the other member, and a thrust elementassociated with said Synchronizer element so as to transmit axial thrustthereto andso as to receive f/ radially outwardly directed thrusttherefrom 4while relative rotation exists between said 'syn- 40 rictionclutch element, whereby tog i.; ea.ri",' interior surface of saidmovable clutch ement under pressure so that it may receive axial thrustfrom said movable clutch element.

5. In a synchronizing transmission, a pair of axially alignedtorque-transmitting members, movable Jaw clutch and synchronizerelements dri'v'higly associated with one member, said clutch elementbeing movable axially and saidsynchronizerelement being adapted to beurged under axial pressure into positive clutching and frictionaldriving engagement, respectively, with j aw and friction clutch elementsdrivingly associated with the other member, and a. thrust elementassociated with saidsynchronizer element so as to transmit axial thrustthereto and so as to receive radially outwardly Adirected thrusttherefrom while relative rotation exists betven said synchronizerelement and its `cooperating friction clutch element, whereby toVfrictionally engage an interior surface of said movable clutch elementunder pressure which will be relaxed when synchronization isattained-.whereby said movable clutc element. as it is urged axially,will transmit to said synchronizerelement axial thrust having anintensity decreasing in response to decreasing relative rotation saidsynchro-v nizer element and its enacting friction clutch element. v

6. In a synchronizing transmission, a pair of axially alignedtorque-transmitting members, movable jaw clutch and synchroniserelements tof Vdrivingly associated with one member, said clutch elementbeing movable and said synchro- 15 nizer element being adapted to beurged under axial pressure into positive clutching and frictionaldriving engagement, respectively, with Jaw and friction clutch elementsdrivingly associated Vwith the other member, and a thrust elementarrangedto transmit axial thrust to said synchro- Y nizer element and tofrictionally engage an interior surface of said movable clutch elementwith an intensity decreasing in. response to decreasing relativerotation between said synchronizer element and the member with which itis engaged.

'1. In a synchronizing transmission', a pair Iof axialhr alignedtorque-transmitting members, movable jaw clutch and synchronizerelements l5 drivingly associated with one member, said clutch elementbeing movable axially and said synchronizer element being adapted to beurged under axial pressure into positive clutching and frictionaldriving engagement, respectively, with jaw and friction clutch elementsdrivingly associated with the other member, and a thrust elementassociated with said synchronizer element so as to transmit axial thrustthereto and so as to receive radially outwardly directedthrusttherefromwhile 25 relative rotation exists between saidsynchronizer element and its cooperating friction clutch element,whereby to frictionally engage an interior surface of said movableclutch-element under pressure which Will be relaxed when synchro- 80nizatlon is attained, whereby said movable clutch element, as it isurged axially, will transmit to said synchronizer element axial thrusthaving an intensity decreasing in response to decreasingrelatiiegrctation between said synchronizer ele- //met and its coactingfriction clutch element and relaxing substantially entirely whensynchronization is attained.`

8. In a synchronizing transmission, a pair of axially alignedtorque-transmitting members, 44)4 movable jaw clutch and synchronizerelements drivingly associated with one member, said clutch element beingmovable axially and said synchronizer element being adapted to be urgedunder axial pressure into positive clutching and fric- 5 tional drivingengagement, respectively, with jaw and friction clutch elementsdrivingly associated with the other member, said synchronizer elementbeing arranged to have limited circumferential movement relative to saidmovable clutch 50 element and including blocking means adapted,

when in one limit of such circumferentialrvelY ment, to obstruct axialadvance/of said movable clutch element, and herin another position, toallow said /mcvable clutch element to advance to 55 @tive/clutchingposition, and a thrust member v/-f arranged to frictionally engage aninteriorsurface of said movable clutch element and having an endassociated with said synchronizer element so as to transmit axial thrustthereto and so as to 60 develop a radially outwardly directed frictionalengagement with said movable clutch element of intensity varying inaccordance with the rate of relative rotation between said synchronizerelement and the member with which it is in fric- 65 tional engagement.

9. In a synchronizing transmission, a pair of torque-transmittingmembers mounted, in axial alignment, an annular movable jaw clutchelement surrounding and carried by one of said 70 members and adapted tobe moved into engagement with a jaw clutch element drivingly-associatedwith the other membenthus to establish a positive drive connectionbetween said members, said clutch element being provided with an 75internal axially extending, substantially semicylindrical notch, asynchronizer ring associated with said one torque-transmitting member,and v having a circumferentially elongated recess, means fortransmitting axial thrust from said movable clutch element to saidsynchronizer ring, 5

said means comprising a cylindrical thrust member positioned in saidnotch having an end region extending into said recess and adapted toengage a portion of the synchronizer ring to transmit axial thrustthereto, and to engage circum- 10 ferentially spaced regions of saidrecess so as to provide a lost motion driving connection between thesynchronizer ring and the movable clutch element.

10. In a synchronizing transmission, a pair of torque-transmittingmembers mounted in axial alignment, an annular movable jaw clutchelement surrounding and carried by oneof said members and adapted to bemoved into engagement with a :law clutch element carriedby the othermember, thus to establish a positive drive connection between saidmembers, a synchronizer ring associated with said onetorque-transmitting member and having a circumferentially elongatedrecess, and a thrustvmember interposed between Said movableclutch'element and said synchro- 'nizer ring,'said thrust member havingan end transmit axial thrust thereto, and to engage circumferentiallyspaced regions of said recess so as to provide a lost motion drivingconnection between the synchronizer ring and the movable clutch element,said recess having a radially outwardly facing circumferentiallyinclined ramp 3" adapted to engage said end region of the thrust memberand to wedge the thrust member against the movable clutch element so asto provide frictional engagement for transmitting axial thrust from themovable clutch element to the thrust member.

11. In a synchronizing transmission, a pair of torque-transmittingmembers mounted in axial alignment, an annular movable jawgclutchelementsurrounding and vcarried by one of said members and adapted to be movedinto engagement with a. jaw clutch element carried by the ring'associated with said one torque-transmitting 50 member and having acircumferentially elongated recess, and a thrust bar arranged parallelto the axis of said members and operatively interposed between saidmovable clutch element and -said synchronizer ring, said thrust barhaving an end region extending into said recess Aand adapted to engage aportion of the synchronizer ring to transmit axial thrust thereto, andto engage circumferentially spaced regions of said recess so as toprovide a lost motion driving connection 60 between the synchronizerring and the movable clutch element, said recess having a radiallyoutwardly facing circumferentially inclined ramp adapted to engage saidend region of the thrust bar and to wedge the thrust bar against themovable clutch element so as to provide frictional en gagement fortransmitting axial thrust from the movable clutch element to the thrustmember.

12. In a synchronizing transmission, a pair of torque-transmittingmembers mounted in axial 7o alignment, an annular movable jaw clutchelement surrounding and carried by one of said members and adapted to bemoved into'engage'- ment with a jaw clutch element drivinglyassoelated.l with the other member, thus-'to establish 75 a positivedrive connection between said members, a synchronizer element associatedwith said one torque-transmitting member and adapted to be urged underaxial pressure into frictional driving engagement with said othertorque-transmitting member, a plurality of thrust bars disposed tbetween said movable clutch element and said `creasing in response todecrease 15. In a synchronizing transmission, apair of onetorque-transmitting member, parallel to the axisof said members, andhaving purely frictional engagement with interior surfaces of saidmovable clutch element, and an annular spring arranged to yieldinglyurge said bars radially outwardly into such frictional engagement, saidbars being arranged to transmit thrust from said movable clutch elementto said synchronizer element.

13. In a synchronizing transmission, a pair oi` axially alignedtorque-transmitting members, movable jaw clutch and synchronizerelements drivingly associa-ted with said one member, said clutch elementbeing movable axially and said synchronizer element being adapted tobeurged under axial pressure into positive Vclutching and frictionaldriving engagement, respectiilywith\- jaw and friction clutch elementsdrivingly associated with the other member, said synchronizer elementbeing arranged to have limited circum-- ferential -movement relative tosaid movable clutch element and including blocking means adapted, whenin one limit of such circumferential movement, to obstruct axial advanceof said movable clutch element, and when in another position, to allowsaid movable clutch element to advance to positive clutching position,and 'a` thrust member arranged to frictionally engage an interiorsurface of said movable clutch element, said synchronizer element havinga ramp surface adapted to exert radially outwardly directed pressureagainst said thrust member, of intensity dein relative rotation of saidsynchronizer element and its coacting frictionl clutch element. "f

14. In a synchronizing transmission, a pair of axiallyalignedrtorque-.transmitting members; av movable jaw clutch sleevesplined on one of said members for axial movement into positiveclutching engagement with a Jaw clutch element drivingly associated'withchronizer ring associated with said one member, adapted to be urgedunder axial pressure into frictional driving engagement with said othermember, arranged to Vhave limited circumferen; tial movement relative tosaid s1eeve,'and including blocking means adapted. when in one limit` ofsuch circumferential movement, to obstruct axial advance of said sleeveand, when in another position, to=allow saidsleeve to advance topositive clutching position, and a thrust bar, parallel to the axis ofsaid members, arranged to frictionally engage an interior surface ofsaid sleeve with an intensity decreasing in response to decreasingrelative rotation between said synchronizer ring and the member withwhich it is engaged, and to transmit axial thrust from said sleeve tosaid synchronizer ring.

torque-transmitting members mounted in axial alignment. an annularmovable jaw clutch eleconnection` between ment surrounding and carriedby one of said members and adapted to be moved into engagement with ajaw clutch element carried'by the other member, thus to establish apositive drive said a synchronizer element associated with said'onetorque-transmitting member and adapted to be urged imder Y pletion ofsynchronization.

axial pressure into frlctional driving engagement with said othertorque-transmitting member, a thrust bar loosely received. between saidmovable clutch element and said one torque-transmitting member parallelto the axis of said members. one end of saidbar being engageable with aradially outwardlyfacing surface of said synchronizer element, andadapted to transmit axial thrust from said movable clutch element tosaid synchronizer element, and resilient means arranged to urge theother end of said bar radially outwardly whereby, when said movableclutch element is in positive clutch engaged position, said bar mayfulcrum against an edge thereof so that its said one end may be urgedradially inwardly l5 into engagement withthe synchronizer element as aresult of the radially outward pressure against its said other end.

16. In a synchronizing transmission, a pair of torque-transmittingmembers mounted in axial 20 alignment, a movable jaw clutch elementcarried by one of said members and adapted to be moved into engagementwith' a jaw clutch element carriedby the other member, thus to establisha positive driverccnngion between said members. a'25 synchronizerelement-ha@ a lost motion driving connection with said one nemberialdincluding blocking means adapted, infone of itspos'i-M tions permittedby said lost motion connection, to block the path of axial shiftingmovement of said 30 movable clutch element and, in another of suchpositions, to allow the movable clutch element to complete its axialshifting movement,rsaid synchronizer element having a friction clutchfacev associated with a coacting friction" clutch face on said othermember, and a spring loaded telescoping thrust member arranged to exert'a'constant light yielding pressure against said synchronizer element soas to cause the same to constantly receive torque='from saidcoacting'friction clutch 46 plate and to thereby be biased in blochngrelation to said movable clutch element', -said thrust member having apurely frictional engagement with said movable clutch 'elementi adaptedto transmit axial thnistfromusaid movable clutch element to saidsynchronizer element for auginenting said biasing action. wherebyengagement the other member, da-sigan movable clutch element againstsaid blocking means may serve to transmit to the synchronizer-elementsinllcient axial force for com 17. In a synchronizing transmission, apair of axially aligned torque-transmitting members te be synchronized,movable'iaw clutch and synchronizer elements drivingly associatedwithone member, said Jaw clutch element being movable axially and saidsynchronizer element being adapted to be urged under axial pressure intopositive clutching and frictional driving engagement respectively withjawv and frictionl clutch elements drivingly associated with the-othermember, a plurality of thrust bars disposed between said movable clutchelement and said one torquetransmitting member, parallel to the axis ofsaid members, and adapted to have axial thrust re- Aceiving engagementwith interior regions of `said movable clutch element, and toV transmitthe thrust thus received to said synchronizer element. and an annularspring' arranged to yieldingly urge all of said thrust bars radiallyoutwardly to 9,221,899 l l 7 I member, said jaw clutch element beingmovable axially and said synchronizer element being adapted to be urgedunder axial pressure into positive clutching and frictional drivingengagement respectively with jaw and-friction clutch elements drivinglyassociated with the other member, a plurality of thrust elements adaptedto have thrust receiving engagement with interior regions of saidmovable jaw clutch element and 10 to transmit the thrust thus receivedlto said synchronizer element, and an annular spring engaging andyieldingly urging'all of said thrust elements radially outwardly toestablish said thrust receiving engagement with the movable clutchelement. 19. A synchronizing transmission as deinedin claim 17, whereinsaid ring engages each thrust bar near one end thereon.

20. In a synchronizing transmission, a hub, a

movable jaw clutch sleeve splined upon the rimthereof and shiftableaxially into positive clutching engagement with a member to besynchronized with said hub, a synchronizer'ring having an axiallyextending ange axially recessed into said hub and having a radiallyoutwardlyprojecting flange, a plurality of thrust bars interposedbeltween. said hub and the movable jaw clutch element, their endsadapted to engage said radially outwardly projecting iiange for urgingsaid synchronizer ring into engagement with a cooperating frictionclutch element drivingly associated with said member to be synchronized,and an i annular spring disposed -between the rim of said hub and saidradially outwardly projecting ange,

encircling said axially extending flange, and engaging end regions ofsaid thrust bars so as to urge them radially outwardly into axial thrustreceiving engagement with interior regions of said movable jaw clutchelement.

n 21. In a synchronizing transmission, a pair of axially aligned torquetransmitting members to be synchronized, movable jaw clutch andsynchronizer elements drivingly associated with one member, said jawclutch element being movable axially and said synchronizer element beingadapted to be urged under axial pressure into positive clutching andfrictional driving engage- .ment respectively with jaw and frictionclutch elements drivingly associated with the other member, thesynchronizer ring being arranged to' have limited circlnnferentialmovement relative to said movable .law clutch element, and includingblocking means adapted, when in one limit ci such circumferentialmovement, to be engaged by and to receive thrust from said movable Jawclutch element for eifecting synchronization, and a spring loadedtelescoping member arranged to exert a constant light yielding pressureagainst said synchronizer element so as to cause the same to be normallybiased in4 blocking position as a result of light transmission of torquebetween the friction surfaces. 1

22; In a synchronizing n, a hub, a

-pair of axially `spaced torque transmitting :mem-

g5 bers between which said-hub is mounted in axial alignment therewith,a movable jaw clutch sleeve encircling said hub, drivingly connectedthereto,

and axially shiftable thereon into positive clutching engagement withpositive clutch elements n drivingly associated with the respectivetorque transmitting members, thereby to establish a positive driveconnection between said hub and either of said members, a pair ofsynchronizer elements each having a lost motion driving connection withsaid hub and including blocking means adapted 25 in one of its positionspermitted by said lost motion connection, to block the path of axialshifting movement of said movable jaw clutch sleeve and,

in another of such positions, to allow the mov- .l able jaw clutchsleeve to complete its axial shift- 10 ing movement,l saidsynchronizerelements each having a frictionl clutch face associated with a coactingfriction clutch element drivingly associated with an adjacent torquetransmitting member and adapted tobe urged intc frictional driving 15engagement therewith by axial pressure derived through the blockingengagement of said blocking means and movable'jaw clutch sleeve, wherebyto effect synchronization between said hub and the corresponding torquetransmitting member, 20 and means `for causing the synchronizer elementsto constantly receive torque from thelrrcoacting friction clutchelements and to thereby be biased in their blocking positions so as toinsure initiation of synchronization, said means comprising 25.

an axially yieldablel elongated element disposed between the hub andsaid movable jaw clutch sleeve and having its ends engaged undercompression against the respective synchronizer elements. 3 23. In asynchronizing transmission, a hub, a pair of axially spaced torquetransmitting members between which said hub is mounted in axial ahgnmenttherewith, a movable jaw clutch sleeve encircling said hub, drivinglyconnected thereto, 35;

= by said lost motion connection, to block the path 45 of axial shiftingmovement of said movable jaw .clutch sleeve and, in another of suchpositions, to allow the movable jaw clutch sleeve to complete its axialshifting movement. -said synchronizer elements each having a frictionclutch face 50 associated with a coacting friction clutch element,

, drivingly associated .with an adjacent torque transmitting member andadapted to beurged into frictional driving engagement therewith by axialpressure derived through the blocking en- 55 gagement of said blockingmeans and movable` jaw clutch sleeve, whereby to eifect synchronizationbetween -saidhub and the corresponding torque transmitting member, andmeans for causing the synchronizer elements to constantly resa ceivetorque from their coacting friction clutch elements and to thereby bebiased in their block@ ing positions so\as. to insure initiation ofsynchronization, said means comprising an axially yieldable elongatedelement extending axially of o5 the hub and having'its ends engagedunder compression against said synchronizer elements.

-BAMUEL 0.A WHITE. PANIER. ORR 7o

